Hydrogen is a radiolysis product of water and other food
components. Usually it diffuses away rapidly, but researchers have found
that hydrogen can be useful as a marker for irradiated frozen chicken.
The technique for measuring hydrogen levels involves using an electronic
sensor incorporated into a headspace analyzer. This makes it attractive
as an inexpensive onsite screening procedure. The technique works well
with frozen foods that can be thawed inside the analyzer. You need
samples of at least 100 g to confidently detect irradiated doses greater
than 0.5 kGy after 15 weeks of storage at -20 C. A similar procedure is
applicable to other solid foods, such as eggshells, that can be
dissolved inside the analyzer. However, the failure to detect hydrogen
levels is not proof that a sample has not been irradiated. Contact:
Christopher Hitchcock, the University of Surrey Food Safety Research
Group, School of Biological Sciences, Guildford, Surrey GU2 5XH,
England, U.K. Phone: +44 1234 344407. Fax: +44 1483 576978. URL:
http://www.surrey.ac.uk.

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